my player suddenly out of form

league: lost to -8Q team (possibly -5Q in best 11) where all the player drop form and got only 6-7 (i didn't watch the match opponent neither)
CL: have only equalised at 73 minutes and got winning goal at 85th minutes. opponent is 15Q lower

why they plays so good in the cup but amater in League and champion league this season !!!